Guide apparatus for drafting inking



1965 A. M lLVAlNE DUGGAN 3,225,445

GUIDE APPARATUS FOR DRAFTING INKING Filed Aug. 19, 1963 INVENTOR. A. M: /L l/AINE DUGGAN \EEQQQN ATTORNEY United States Patent 3,225,445 GUlDE APPARATUS FGR DRAFTING INKING Aloysius Mcllvaine Duggan, 189 N. Marengo Ave., Pasadena, Calif. Filed Aug. 19, 1963, Ser. No. 303,014 3 Claims. (Cl. 33-107) The invention relates to instruments for guiding inking pens in drafting work, and more particularly to guide apparatus to permit use of modern reservoir pens.

Drafting pens have changed in character and capabilities during the last two decades. No special drafting instruments are presently being marketed to work compatibly with the newer ruling pens. I have invented guide apparatus that affords a smooth guide surface for the tips of the new pens as well as for the nibs of conventional ruling pens, and that minimizes contact between the guide apparatus and the working surface of the drawing paper upon which the inked line is being ruled. Minimum contact between the guide apparatus and the surface reduces the amount of soil that the working surface absorbs. While those sheets of drawing which must be inked would benefit most from the invention, pencilled only sheets would also be cleaner.

The invention contemplates guide apparatus that comprises a ruling instrument (such as a conventional triangle, curve or T-square), a guide edge on the instrument and a plurality of contact means on the instrument adapted to raise the instrument above the working surface. Each contact means is attached to the ruling instrument such that each contact means has a diminishing transverse area as the means projects away from the instrument.

Preferably the contact means is a spherical protrusion from the bottom surface of the guide instrument. A conical contact means may also be used. The contact means may be a sphere that projects in part from obverse and reverse sides of the ruling instrument where such instrument is variously oriented in use. When the contact means is a full sphere it is possible to mount it so that it rotates with respect to the instrument, thereby reducing frictional contact upon the working surface.

Since each contact means projects from that surface of the ruling instrument normally contiguous to the working surface, the instrument is supported above the working surface thereby. Only the contact means, of which there may be several, touch the working surface.

These and other advantages of the invention are apparent from the following detailed description and drawing in which:

FIG. 1 is a perspective view of a pair of associative ruling instruments in accordance with the invention;

FIG. 2 is a fragmentary side elevation of a ruling instrument in accordance with the invention and showing the contacting means thereon;

FIG. 3 is a fragmentary plan view of a straightedge ruling instrument combined with contacting means in accordance with the invention; and

FIG. 4 is a fragmentary sectional elevation taken along line 4-4 of FIG. 3.

In FIG. 1 a conventional straightedge ruling instrument 11, shown without its parallel cord arrangement, is shown in perspective associated with a so-called 3060 triangle 12. The straightedge and the triangle are lying upon the drawing or working surface 14 of a sheet of drafting paper 15, shown fragmentarily. The triangle has a plurality of guide edges 12A, 12B, 12C, while straightedge 11 has a pair of parallel guide edges 11A and 11B. Guide edges 11A and 12C of the straightedge and the triangle, respectively, are juxtaposed.

The visible upper surface 17 of triangle 12 has protruding therefrom hemispherical contacting means 18, 19, 20.

3,225,445 Patented Dec. 28, 1965 Similar contacting means (not shown) are in vertical alignment with contacting means 18, 19, 20 and protrude from the lower surface of the triangle.

A similar triangle 21 is shown fragmentarily in FIG. 2, where attachment means 22, 23 fix contacting means 24, 25 to the obverse and reverse surfaces of the triangle.

Triangle 12 of FIG. 1 has the contacting means adhered thereto by means of a flange 26 of thin wafer'like construction. Each contacting means 18, 19, 20 has a similar flange. The contacting means and flange may be formed integrally and be a hollow hemispherical stamp with a flange. The hemispherical contacting means 21 and 24 of FIG. 2 are fixed to the obverse and reverse faces of triangle 21 by convenient means, such as tiny rivets 31, passing through attachment means flanges 22, 23. Ohviously, many other forms of attachment and construction can be used, such as formed ruling instruments from which contacting protuberances extend.

Returning again to FIG. 1, note that straightedge 11 has attached thereto pairs of spheres 34, 35 and 36, 37. As shown in FIG. 4, the lowest point of sphere 34 protrudes a distance H below undersurface 39 of straight edge 11. Each of the sphere pairs is retained in a shaped annulus 41 in a retainer strip 43 that extends outwardly beyond the guide edges of the straightedge. The retainer strip is of very thin material, so that most of the elevation of undersurface 39 is due to the projection of the hemispheres rather than the thickness of the retainer strip. In FIG. 4 material thicknesses have been exaggerated for the purpose of illustration.

Each retainer strip containing two spheres is held in place upon the straightedge by a shaped top clamp 45. Preferably the clamps are placed about the straightedge at each of its ends and then secured to the retainer strips by convenient fasteners, such as small screws or pins.

As is evident from FIG. 1, the elevations above the working surface 14 of both the guide edge of the triangle and the guide edge of the straightedge must be of the same order so that the two instruments may be associated in working arrangement. Some adjustment is available in the retaining strips 43, since their outer ends may be bent upwardly or downwardly in small measure to achieve proper planar alignment between triangle and straightedge guide edges.

The illustrative figures disclose spheres or hemispheres protruding from retaining means to elevate the bottom surfaces of the ruling instruments. The spherical shape is preferable because it minimizes the rubbing contact with the working surface of the drawing. However, conical contacting means may be utilized. Polished tip surfaces on the contacting means are also desirable.

By proper selection of fit between sphere 34 and its retaining annulus 41, the sphere may be retained in proper position and still rotate within the annulus as the instrument is moved across the working surface. The rotating action tends to decrease the amount of grit and other soil rubbed into the drawing surface. Obviously, the same mechanical arrangement can be provided for other mounting arrangements. A sphere may be substituted for hemispheres.

The ruling instruments as illustrated have been found to work exceedingly well with the reservoir-type pens with stylus points that are conventionally used for drafting. The best results have been obtained when proper allowance is made in elevating the guide edges of the instruments for the various types of styli presently in use. Different makes and sizes of pens vary in stylus construction. It has been found that the lowest edge of the guiding edge should be elevated at least of an inch above the working surface. The upper edge of the guiding edge of the ruling instrument is preferably no more than of an inch above the working surface. These limitations as to edge arrangement are not necessarily perfect for any one stylus pen, but define an optimum condition for use with most conventional stylus pens. The older type of nibs pen is easily used with the instruments of the invention.

In addition to elevating from contact most of the dirt distributing surfaces of the ruling instruments, the plurality of contact means, by the elevation also eliminates the capillary flow of ink from the stylus pens, and of nibs pens, between the bottom surface of the ruling instrument and the working surface of the drawing. Because the invention provides for as few as three points of contact between a ruling instrument and the drawing, inked drawings may be accomplished with no need for extensive erasing on completion, with the subsequent fading of inked lines.

While the disclosed embodiments illustrate the invention, they do not encompass the full range of embodiments possible to the invention. Those skilled in the art will perceive many varied forms within the scope of the invention, which is defined by the appended claims.

I claim:

1. Guide apparatus for ruling inked lines upon a working surface comprising a ruling instrument having a bottom surface, a guiding edge on the instrument, a plurality of attachment means fixed to the ruling instrument, each attachment means having a top clamp and a retainer strip with ends extending beyond the guiding edges of the ruling instrument, a protruding contact means held by each attachment means and adapted to raise the bottom surface of the instrument above the working surface, each contact means diminishing in its horizontal cross-sectional area away from the said bottom surface of the instrument.

2. Apparatus in accordance with claim 1 wherein each contact means is free to rotate with respect to the attachment means.

3. Apparatus in accordance with claim 1 wherein each retainer strip end is sufficiently pliant to be adjustable with respect to horizontal line of the ruling instrument.

References Cited by the Examiner UNITED STATES PATENTS 864,396 8/1907 Weston 33107 1,012,340 12/1911 Du Pont 33104 1,145,922 7/1915 Rigaumont.

1,498,994 6/1924 Borsuk 33-104 1,584,839 5/1926 Cameron 33-107 FOREIGN PATENTS 17,346 7/1894 Great Britain.

ISAAC LISANN, Primary Examiner.

ROBERT B. HULL, Examiner. 

1. GUIDE APPARATURS FOR RULING INKED LINES UPON A WORKING SURFACE COMPRISING A RULING INSTRUMENT HAVING A BOTTOM SURFACE, A GUIDING EDGE ON THE INSTRUMENT, A PLURALITY OF ATTACHMENT MEANS FIXED TO THE RULING INSTRUMENT, EACH ATTACHMENT MEANS HAVING A TOP CLAMP AND A RETAINER STRIP WITH ENDS EXTENDING BEYOND THE GUIDING EDGES OF THE RULING INSTRUMENT, A PROTRUDING CONTACT MEANS HELD BY EACH ATTACHMENT MEANS AND ADPATED TO RAISE THE BOTTOM SURFACE OF THE INSTRUMENT ABOVE THE WORKING SURFACE, EACH CONTACT MEANS DIMINISHING IN ITS HORIZONTAL CROSS-SECTIONAL AREA AWAY FROM THE SAID BOTTOM SURFACE OF THE INSTRUMENT. 